Integrated test systems for component testing in a burn-in chamber are well known; for example, semi-conductor life tests in burn-in chambers are common. The process of burning-in typically consists of applying a load to the components being tested as elevated temperatures. This allows indentification of weak or faulty components, and thus, precludes the ultimate use such as in a computer system. The burn-in chambers generally comprise a plurality of paired tracks which carry the burn-in trays, connectors and a power supply.
The burn-in trays typically comprise a pan and an integrated circuit board which board includes connectors, sockets, etc., secured thereto. The sockets may be longitudinally bussed to a ribbon plug as is well known. There may be positioned in the sockets any number of elements to be tested, for example, semi-conductor devices, integrated circuits, etc. With commercially available burn-in trays, a longitudinal circuit board containing sockets and associated components, such as resistors, is secured to the rectangular pan. The sockets are arranged in parallel rows transverse to the longitudinal axis of the board.
In the earlier boards commercially available, discrete resistors were connected to the contacts in the sockets and were simply layed on the boards in a flat position adjacent the sockets. Presently, in order to achieve a greater density of sockets on a tray, thus allowing a greater quantity of integrated circuits or the like to be tested at one time in one particular location in a burn-in chamber, the resistors are joined to the sockets in an upright vertical position allowing a greater number of sockets per unit area.
In these systems, where the resistors are upright, they are connected to individual contacts in the dip burn-in sockets. These contacts extend over the upper edge of the body of the socket and then extend downwardly and upwardly in side-by-side spaced relationship. In actuality, these contacts which are welded to one lead of an associated resistor are typically very close and rigid. This results in accidental dislodging of the contacts during loading and unloading of the IC's, whereby they may either break or be distorted resulting in shorting out or more generally, damage to the contacts.
The present invention is directed to a configuration of contacts in dip burn-in circuits which overcome the problems of high frequency damage and/or shorting endemic in prior art configurations.
Broadly, in my invention a socket adapted to receive an IC or the like, includes a body with outer opposed walls having upper edges and a plurality of substantially flat contacts biased to a closed position within the socket body to receive the leads of an IC to be tested. The contacts extend over the upper edge of at least one wall and then are turned downwardly forming a necked section of reduced width compared to the width of the contact disposed within the socket body. The contact terminates in a depending end having a concave surface adapted to engage a lead of an associated resistor.
The contact within the socket body is restrained from lateral movement by walls within the socket body. The reduction in width is approximately one-half, i.e., the necked portion compared to the width of the contact within the socket body. Alternatively, the contacts on both sides of the socket body are formed in a like manner. In a particularly preferred embodiment, the depending end is C-shaped and adapted to receive in frictional engagement the lead of a resistor.